Table 1.

Findings of effective linear and nonlinear methods for detecting dementia [55, 107, 121, 122, 131].

	Methods		Finding
Linear techniques	Spectral analysis	Median frequency (MF)	Dementia is associated with a slowing of brain frequencies
		Spectral entropy (SpecEn)	Dementia causes a change in the frequency content of the brain signals
	Zero crossing interval (ZCI)		ZCI increased in slow activity associated with dementia
Nonlinear techniques	Fractal dimension (FD)		FD of the EEG is lower for dementia patients than normal subjects
	Lempel-Ziv-Welch (LZW)		Lower LZW of dementia patients than normal subjects due to reduce complexity
	Tsallis entropy (TsEn)		Lower TsEn in AD group than the normal